The human body is an incredibly complex
and intricate system, one that still baffles doctors and
researchers on a regular basis despite thousands of years of medical knowledge.
As a result, it
shouldn’t be any surprise that even body parts and functions we deal
with every day have bizarre
or unexpected facts and explanations behind them. From sneezes to fingernail
growth, here are
100 weird, wacky, and interesting facts about the human body.

The Brain

The human brain is the most complex and least understood part of the human
anatomy. There
may be a lot we don’t know, but here are a few interesting facts that
we’ve got covered.
1. Nerve impulses to and from the brain travel as fast as 170 miles per
hour. Ever
wonder how you can react so fast to things around you or why that stubbed
toe hurts right
away? It’s due to the superspeedy movement of nerve impulses from
your brain to the
rest of your body and vice versa, bringing reactions at the speed of a high
powered luxury
sports car.
2. The brain operates on the same amount of power as 10 watt light bulb.
The cartoon
image of a light bulb over your head when a great thought occurs isn’t
too far off the
mark. Your brain generates as much energy as a small light bulb even when
you’re
sleeping.
3. The human brain cell can hold 5 times as much information as the Encyclopedia
Britannica. Or any other encyclopedia for that matter. Scientists have yet
to settle on a
definitive amount, but the storage capacity of the brain in electronic terms
is thought to
be between 3 or even 1,000 terabytes. The National Archives of Britain,
containing over
900 years of history, only takes up 70 terabytes, making your brain’s
memory power
pretty darn impressive.
4. Your brain uses 20% of the oxygen that enters your bloodstream. The brain
only
makes up about 2% of our body mass, yet consumes more oxygen than any other
organ in
the body, making it extremely susceptible to damage related to oxygen deprivation.
So
breathe deep to keep your brain happy and swimming in oxygenated cells.
5. The brain is much more active at night than during the day. Logically,
you would
think that all the moving around, complicated calculations and tasks and
general
interaction we do on a daily basis during our working hours would take a
lot more brain
power than, say, lying in bed. Turns out, the opposite is true. When you
turn off your
brain turns on. Scientists don’t yet know why this is but you can
thank the hard work of
your brain while you sleep for all those pleasant dreams.
6. Scientists say the higher your I.Q. the more you dream. While this may
be true, don’t
take it as a sign you’re mentally lacking if you can’t recall
your dreams. Most of us don’t
remember many of our dreams and the average length of most dreams is only
23
seconds–barely long enough to register.
7. Neurons continue to grow throughout human life. For years scientists
and doctors
thought that brain and neural tissue couldn’t grow or regenerate.
While it doesn’t act in
the same manner as tissues in many other parts of the body, neurons can
and do grow
throughout your life, adding a whole new dimension to the study of the brain
and the
illnesses that affect it.
8. Information travels at different speeds within different types of neurons.
Not all
neurons are the same. There are a few different types within the body and
transmission
along these different kinds can be as slow as 0.5 meters/sec or as fast
as 120 meters/sec.
9. The brain itself cannot feel pain. While the brain might be the pain
center when you cut
your finger or burn yourself, the brain itself does not have pain receptors
and cannot feel
pain. That doesn’t mean your head can’t hurt. The brain is surrounded
by loads of tissues,
nerves and blood vessels that are plenty receptive to pain and can give
you a pounding
headache.
10. 80% of the brain is water. Your brain isn’t the firm, gray mass
you’ve seen on TV.
Living brain tissue is a squishy, pink and jelly-like organ thanks to the
loads of blood and
high water content of the tissue. So the next time you’re feeling
dehydrated get a drink to
keep your brain hydrated.

Hair and Nails

While they’re not a living part of your body, most people spend a
good amount of time caring for
their hair and nails. The next time you’re heading in for a haircut
or manicure, think of these
facts.
11. Facial hair grows faster than any other hair on the body. If you’ve
ever had a
covering of stubble on your face as you’re clocking out at 5 o’clock
you’re probably
pretty familiar with this. In fact, if the average man never shaved his
beard it would grow
to over 30 feet during his lifetime, longer than a killer whale.
12. Every day the average person loses 60100 strands of hair. Unless you’re
already
bald, chances are good that you’re shedding pretty heavily on a daily
basis. Your hair loss
will vary in accordance with the season, pregnancy, illness, diet and age.
13. Women’s hair is about half the diameter of men’s hair. While
it might sound strange,
it shouldn’t come as too much of a surprise that men’s hair
should be coarser than that of
women. Hair diameter also varies on average between races, making hair plugs
on some
men look especially obvious.
14. One human hair can support 3.5 ounces. That’s about the weight
of two full size candy
bars, and with hundreds of thousands of hairs on the human head, makes the
tale of
Rapunzel much more plausible.
15. The fastest growing nail is on the middle finger. And the nail on the
middle finger of
your dominant hand will grow the fastest of all. Why is not entirely known,
but nail
growth is related to the length of the finger, with the longest fingers
growing nails the
fastest and shortest the slowest.
16. There are as many hairs per square inch on your body as a chimpanzee.
Humans are
not quite the naked apes that we’re made out to be. We have lots of
hair, but on most of
us it’s not obvious as a majority of the hairs are too fine or light
to be seen.
17. Blondes have more hair. They’re said to have more fun, and they
definitely have more
hair. Hair color determines how dense the hair on your head is. The average
human has
100,000 hair follicles, each of which is capable of producing 20 individual
hairs during a
person’s lifetime. Blondes average 146,000 follicles while people
with black hair tend to
have about 110,000 follicles. Those with brown hair fit the average with
100,000 follicles
and redheads have the least dense hair, with about 86,000 follicles.
18. Fingernails grow nearly 4 times faster than toenails. If you notice
that you’re
trimming your fingernails much more frequently than your toenails you’re
not just
imagining it. The nails that get the most exposure and are used most frequently
grow the
fastest. On average, nails on both the toes and fingers grow about one tenth
of an inch each month.
19. The lifespan of a human hair is 3 to 7 years on average. While you quite
a few hairs
each day, your hairs actually have a pretty long life providing they aren’t
subject to any
trauma. Your hairs will likely get to see several different haircuts, styles,
and even
possibly decades before they fall out on their own.
20. You must lose over 50% of your scalp hairs before it is apparent to
anyone. You lose
hundreds of hairs a day but you’ll have to lose a lot more before
you or anyone else will
notice. Half of the hairs on your pretty little head will have to disappear
before your
impending baldness will become obvious to all those around you.
21. Human hair is virtually indestructible. Aside from it’s flammability,
human hair
decays at such a slow rate that it is practically nondisintegrative.
If you’ve ever wondered how your how clogs up your pipes so quick
consider this: hair cannot be
destroyed by cold, change of climate, water, or other natural forces and
it is resistant to
many kinds of acids and corrosive chemicals.

Internal Organs

Though we may not give them much thought unless they’re bothering
us, our internal organs are
what allow us to go on eating, breathing and walking around. Here are some
things to consider
the next time you hear your stomach growl.
22. The largest internal organ is the small intestine. Despite being called
the smaller of the
two intestines, your small intestine is actually four times as long as the
average adult is
tall. If it weren’t looped back and forth upon itself it wouldn’t
fit inside the abdominal
cavity.
23. The human heart creates enough pressure to squirt blood 30 feet. No
wonder you can
feel your heartbeat so easily. Pumping blood through your body quickly and
efficiently
takes quite a bit of pressure resulting in the strong contractions of the
heart and the thick
walls of the ventricles which push blood to the body.
24. The acid in your stomach is strong enough to dissolve razorblades. While
you
certainly shouldn’t test the fortitude of your stomach by eating a
razorblade or any other
metal object for that matter, the acids that digest the food you eat aren’t
to be taken
lightly. Hydrochloric acid, the type found in your stomach, is not only
good at dissolving
the pizza you had for dinner but can also eat through many types of metal.
25. The human body is estimated to have 60,000 miles of blood vessels. To
put that in
perspective, the distance around the earth is about 25,000 miles, making
the distance your
blood vessels could travel if laid end to end more than two times around
the earth.
26. You get a new stomach lining every three to four days. The mucuslike
cells lining the walls of the stomach would soon dissolve due to the strong
digestive acids in your
stomach if they weren’t constantly replaced. Those with ulcers know
how painful it can
be when stomach acid takes its toll on the lining of your stomach.
27. The surface area of a human lung is equal to a tennis court. In order
to more
efficiently oxygenate the blood, the lungs are filled with thousands of
branching bronchi
and tiny, grapelike alveoli. These are filled with microscopic capillaries
which oxygen
and carbon dioxide. The large amount of surface area makes it easier for
this exchange to
take place, and makes sure you stay properly oxygenated at all times.
28. Women’s hearts beat faster than men’s.The main reason for
this is simply that on
average women tend to be smaller than men and have less mass to pump blood
to. But
women’s and men’s hearts can actually act quite differently,
especially when
experiencing trauma like a heart attack, and many treatments that work for
men must be
adjusted or changed entirely to work for women.
29. Scientists have counted over 500 different liver functions. You may
not think much
about your liver except after a long night of drinking, but the liver is
one of the body’s
hardest working, largest and busiest organs. Some of the functions your
liver performs
are: production of bile, decomposition of red blood cells, plasma protein
synthesis, and
detoxification.
30. The aorta is nearly the diameter of a garden hose. The average adult
heart is about the
size of two fists, making the size of the aorta quite impressive. The artery
needs to be so
large as it is the main supplier of rich, oxygenated blood to the rest of
the body.
31. Your left lung is smaller than your right lung to make room for your
heart. For most
people, if they were asked to draw a picture of what the lungs look like
they would draw
both looking roughly the same size. While the lungs are fairly similar in
size, the human
heart, though located fairly centrally, is tilted slightly to the left making
it take up more
room on that side of the body and crowding out that poor left lung.
32. You could remove a large part of your internal organs and survive. The
human body
may appear fragile but it’s possible to survive even with the removal
of the stomach, the
spleen, 75 percent of the liver, 80 percent of the intestines, one kidney,
one lung, and
virtually every organ from the pelvic and groin area. You might not feel
too great, but the
missing organs wouldn’t kill you.
33. The adrenal glands change size throughout life. The adrenal glands,
lying right above
the kidneys, are responsible for releasing stress hormones like cortisol
and adrenaline. In
the seventh month of a fetus’ development, the glands are roughly
the same size as the
kidneys. At birth, the glands have shrunk slightly and will continue to
do so throughout
life. In fact, by the time a person reaches old age, the glands are so small
they can hardly
be seen.

Bodily Functions
We may not always like to talk about them, but everyone has to deal with
bodily functions on a
daily basis. These are a few facts about the involuntary and sometimes unpleasant
actions of our
bodies.
34. Sneezes regularly exceed 100 mph. There’s a good reason why you
can’t keep your
eyes open when you sneeze–that sneeze is rocketing out of your body
at close to 100
mph. This is, of course, a good reason to cover your mouth when you sneeze.
35. Coughs clock in at about 60 mph. Viruses and colds get spread around
the office and
the classroom quickly during cold and flu season. With 60 mph coughs spraying
germs
far and wide, it’s no wonder.
36. Women blink twice as many times as men do. That’s a lot of blinking
every day. The
average person, man or woman, blinks about 13 times a minute.
37. A full bladder is roughly the size of a soft ball. No wonder you have
to run to bathroom
when you feel the call of the wild. The average bladder holds about 400-800
cc of fluid
but most people will feel the urge to go long before that at 250 to 300
cc.
38. Approximately 75% of human waste is made of water. While we might typically
think
that urine is the liquid part of human waste products, the truth is that
what we consider
solid waste is actually mostly water as well. You should be thankful that
most waste is
fairly waterfilled, as drier harder stools are what cause constipation and
are much harder
and sometimes painful to pass.
39. Feet have 500,000 sweat glands and can produce more than a pint of sweat
a day.
With that kind of sweat-producing power it’s no wonder that your gym
shoes have a
stench that can peel paint. Additionally, men usually have much more active
sweat glands
than women.
40. During your lifetime, you will produce enough saliva to fill two swimming
pools.
Saliva plays an important part in beginning the digestive process and keeping
the mouth
lubricated, and your mouth produces quite a bit of it on a daily basis.
41. The average person expels flatulence 14 times each day. Even if you’d
like to think
you’re too dignified to pass gas, the reality is that almost everyone
will at least a few
times a day. Digestion causes the body to release gases which can be painful
if trapped in
the abdomen and not released.
42. Earwax production is necessary for good ear health. While many people
find earwax
to be disgusting, it’s actually a very important part of your ear’s
defense system. It
protects the delicate inner ear from bacteria, fungus, dirt and even insects.
It also cleans
and lubricates the ear canal.

Sex and Reproduction

As taboo as it may be in some places, sex is an important part of human
life as a facet of
relationships and the means to reproduce. Here are a few things you might
not have known.
43. On any given day, sexual intercourse takes place 120 million times on
earth. Humans
are a quickly proliferating species, and with about 4% of the world’s
population having
sex on any given day, it’s no wonder that birth rates continue to
increase in many places
all over the world.
44. The largest cell in the human body is the female egg and the smallest
is the male
sperm. While you can’t see skin cells or muscle cells, the ovum is
typically large enough
to be seen with the naked eye with a diameter of about a millimeter. The
sperm cell, on
the other hand, is tiny, consisting of little more than nucleus.
45. The three things pregnant women dream most of during their first trimester
are
frogs, worms and potted plants. Pregnancy hormones can cause mood swings,
cravings
and many other unexpected changes. Oddly enough, hormones can often affect
the types
of dreams women have and their vividness. The most common are these three
types, but
many women also dream of water, giving birth or even have violent or sexually
charged
dreams.
46. Your teeth start growing 6 months before you are born. While few babies
are born
with teeth in place, the teeth that will eventually push through the gums
of young children
are formed long before the child even leaves the womb. At 9 to 12 weeks
the fetus starts
to form the teeth buds that will turn into baby teeth.
47. Babies are always born with blue eyes. The color of your eyes depends
on the genes
you get from your parents, but at birth most babies appear to have blue
eyes. The reason
behind this is the pigment melanin. The melanin in a newborn’s eyes
often needs time
after birth to be fully deposited or to be darkened by exposure to ultraviolet
light, later
revealing the baby’s true eye color.
48. Babies are, pound for pound, stronger than an ox. While a baby certainly
couldn’t
pull a covered wagon at its present size, if the child were the size of
an oxen it just might
very well be able to. Babies have especially strong and powerful legs for
such tiny
creatures, so watch out for those kicks.
49. One out of every 2,000 newborn infants has a tooth when they are born.
Nursing
mothers may cringe at this fact. Sometimes the tooth is a regular baby tooth
that has
already erupted and sometimes it is an extra tooth that will fall out before
the other set of
choppers comes in.
50. A fetus acquires fingerprints at the age of three months. When only
a small fraction
of the way through its development, a fetus will have already developed
one of the most
unique human traits: fingerprints. At only 613
weeks of development, the whorls of what
will be fingerprints have already developed. Oddly enough, those fingerprints
will not
change throughout the person’s life and will be one of the last things
to disappear after
death.
51. Every human spent about half an hour as a single cell. All life has
to begin
somewhere, and even the largest humans spent a short part of their lives
as a single celled
organism when sperm and egg cells first combine. Shortly afterward, the
cells begin
rapidly dividing and begin forming the components of a tiny embryo.
52. Most men have erections every hour to hour and a half during sleep.
Most people’s
bodies and minds are much more active when they’re sleeping than they
think. The
combination of blood circulation and testosterone production can cause erections
during
sleep and they’re often a normal and necessary part of REM sleep.

Senses

The primary means by which we interact with the world around us is through
our senses. Here
are some interesting facts about these five sensory abilities.

53. After eating too much, your hearing is less sharp. If you’re heading
to a concert or a
musical after a big meal you may be doing yourself a disservice. Try eating
a smaller
meal if you need to keep your hearing pitch perfect.
54. About one third of the human race has 20-20 vision. Glasses and contact
wearers are
hardly alone in a world where two thirds of the population have less than
perfect vision.
The amount of people with perfect vision decreases further as they age.
55. If saliva cannot dissolve something, you cannot taste it. In order for
foods, or anything
else, to have a taste, chemicals from the substance must be dissolved by
saliva. If you
don’t believe it, try drying off your tongue before tasting something.
56. Women are born better smellers than men and remain better smellers over
life.
Studies have shown that women are more able to correctly pinpoint just what
a smell is.
Women were better able to identify citrus, vanilla, cinnamon and coffee
smells. While
women are overall better smellers, there is an unfortunate 2% of the population
with no
sense of smell at all.
57. Your nose can remember 50,000 different scents. While a bloodhound’s
nose may be a
million times more sensitive than a human’s, that doesn’t mean
that the human sense of
smell is useless. Humans can identify a wide variety of scents and many
are strongly tied
to memories.
58. Even small noises cause the pupils of the eyes to dilate. It is believed
that this is why
surgeons, watchmakers and others who perform delicate manual operations
are so
bothered by uninvited noise. The sound causes their pupils to change focus
and blur their
vision, making it harder to do their job well.
59. Everyone has a unique smell, except for identical twins. Newborns are
able to
recognize the smell of their mothers and many of us can pinpoint the smell
of our
significant others and those we are close to. Part of that smell is determined
by genetics,
but it’s also largely do to environment, diet and personal hygiene
products that create a
unique chemistry for each person.

Aging and Death

From the very young to the very old, aging is a necessary and unavoidable
part of life. Learn
about the process with these interesting, if somewhat strange facts.
60. The ashes of a cremated person average about 9 pounds. A big part of
what gives the
human body weight is the water trapped in our cells. Once cremated, that
water and a
majority of our tissues are destroyed, leaving little behind.
61. Nails and hair do not continue to grow after we die. They do appear
longer when we
die, however, as the skin dehydrates and pulls back from the nail beds and
scalp.
62. By the age of 60, most people will have lost about half their taste
buds. Perhaps you
shouldn’t trust your grandma’s cooking as much as you do. Older
individuals tend to lose
their ability to taste, and many find that they need much more intense flavoring
in order
to be able to fully appreciate a dish.
63. Your eyes are always the same size from birth but your nose and ears
never stop
growing. When babies look up at you with those big eyes, they’re the
same size that
they’ll be carrying around in their bodies for the rest of their lives.
Their ears and nose,
however, will grow throughout their lives and research has shown that growth
peaks in
seven year cycles.
64. By 60 years of age, 60percent of men and 40percent of women will snore.
If you’ve
ever been kept awake by a snoring loved one you know the sound can be deafening.
Normal snores average around 60 decibels, the noise level of normal speech,
intense
snores can reach more than 80 decibels, the approximate level caused by
a jackhammer
breaking up concrete.
65. A baby’s head is one quarter of it’s total length, but by
age 25 will only be one eighth
of its total length. As it turns out, our adorably oversized baby heads
won’t change size
as drastically as the rest of our body. The legs and torso will lengthen,
but the
head won’t get much longer.

Disease and Injury

Most of us will get injured or sick at some point in our lives. Here are
some facts on how the
human body reacts to the stresses and dangers from the outside world.
66. Monday is the day of the week when the risk of heart attack is greatest.
Yet another
reason to loathe Mondays! A ten year study in Scotland found that 20% more
people die
of heart attacks on Mondays than any other day of the week. Researchers
theorize that it’s
a combination of too much fun over the weekend with the stress of going
back to work
that causes the increase.
67. Humans can make do longer without food than sleep. While you might feel
better
prepared to stay up all night partying than to give up eating, that feeling
will be relatively
short lived. Provided there is water, the average human could survive a
month to two
months without food depending on their body fat and other factors. Sleep
deprived
people, however, start experiencing radical personality and psychological
changes after
only a few sleepless days. The longest recorded time anyone has ever gone
without sleep
is 11 days, at the end of which the experimenter was awake, but stumbled
over words,
hallucinated and frequently forgot what he was doing.
68. A simple, moderately severe sunburn damages the blood vessels extensively.
How
extensively? Studies have shown that it can take four to fifteen months
for them to return
to their normal condition. Consider that the next time you’re feeling
too lazy to apply
sunscreen before heading outside.
69. Over 90% of diseases are caused or complicated by stress. That high
stress job you
have could be doing more than just wearing you down each day. It could also
be
increasing your chances of having a variety of serious medical conditions
like depression,
high blood pressure and heart disease.
70. A human head remains conscious for about 15 to 20 seconds after it is
been
decapitated. While it might be gross to think about, the blood in the head
may be enough
to keep someone alive and conscious for a few seconds after the head has
been separated
from the body, though reports as to the accuracy of this are widely varying.

Muscles and Bones
Muscles and Bones provide the framework for our bodies and allow us to jump,
run or just lie on
the couch. Here are a few facts to ponder the next time you’re lying
around.
71. It takes 17 muscles to smile and 43 to frown. Unless you’re trying
to give your face a
bit of a workout, smiling is a much easier option for most of us. Anyone
who’s ever
scowled, squinted or frowned for a long period of time knows how it tires
out the face
which doesn’t do a thing to improve your mood.
72. Babies are born with 300 bones, but by adulthood the number is reduced
to 206. The
reason for this is that many of the bones of children are composed of smaller
component
bones that are not yet fused like those in the skull. This makes it easier
for the baby to
pass through the birth canal. The bones harden and fuse as the children
grow.
73. We are about 1 cm taller in the morning than in the evening. The cartilage
between
our bones gets compressed by standing, sitting and other daily activities
as the day goes
on, making us just a little shorter at the end of the day than at the beginning.
74. The strongest muscle in the human body is the tongue. While you may
not be able to
bench press much with your tongue, it is in fact the strongest muscle in
your body in
proportion to its size. If you think about it, every time you eat, swallow
or talk you use
your tongue, ensuring it gets quite a workout throughout the day.
75. The hardest bone in the human body is the jawbone. The next time someone
suggests
you take it on the chin, you might be well advised to take their advice
as the jawbone is
one of the most durable and hard to break bones in the body.
76. You use 200 muscles to take one step. Depending on how you divide up
muscle groups,
just to take a single step you use somewhere in the neighborhood of 200
muscles. That’s
a lot of work for the muscles considering most of us take about 10,000 steps
a day.
77. The tooth is the only part of the human body that can’t repair
itself. If you’ve ever
chipped a tooth you know just how sadly true this one is. The outer layer
of the tooth is
enamel which is not a living tissue. Since it’s not alive, it can’t
repair itself, leaving your
dentist to do the work instead.
78. It takes twice as long to lose new muscle if you stop working out than
it did to gain
it. Lazy people out there shouldn’t use this as motivation to not
work out, however. It’s
relatively easy to build new muscle tissue and get your muscles in shape,
so if anything,
this fact should be motivation to get off the couch and get moving.
79. Bone is stronger than some steel. This doesn’t mean your bones
can’t break of course,
as they are much less dense than steel. Bone has been found to have a tensile
strength of
20,000 psi while steel is much higher at 70,000 psi. Steel is much heavier
than bone,
however, and pound for pound bone is the stronger material.
80. The feet account for one quarter of all the human body’s bones.
You may not give
your feet much thought but they are home to more bones than any other part
of your
body. How many? Of the two hundred or so bones in the body, the feet contain
a
whopping 52 of them.

Microscopic Level

Much of what takes place in our bodies happens at a level that we simply
can’t see with the
naked eye. These facts will show you that sometimes that might be for the
best.

81. About 32 million bacteria call every inch of your skin home. Germaphobes
don’t need
to worry however, as a majority of these are entirely harmless and some
are even helpful
in maintaining a healthy body.
82. Humans shed and regrow outer skin cells about every 27 days. Skin protects
your
delicate internal organs from the elements and as such, dries and flakes
off completely
about once a month so that it can maintain its strength. Chances are that
last month’s skin
is still hanging around your house in the form of the dust on your bookshelf
or under the
couch.
83. Three hundred million cells die in the human body every minute. While
that sounds
like a lot, it’s really just a small fraction of the cells that are
in the human body. Estimates
have placed the total number of cells in the body at 1050 trillion so you
can afford to
lose a few hundred million without a hitch.
84. Humans shed about 600,000 particles of skin every hour. You may not
think much
about losing skin if yours isn’t dry or flaky or peeling from a sunburn,
but your skin is
constantly renewing itself and shedding dead cells.
85. Every day an adult body produces 300 billion new cells. Your body not
only needs
energy to keep your organs up and running but also to constantly repair
and build new
cells to form the building blocks of your body itself.
86. Every tongue print is unique. If you’re planning on committing
a crime, don’t think
you’ll get away with leaving a tongue print behind. Each tongue is
different and yours
could be unique enough to finger you as the culprit.
87. Your body has enough iron in it to make a nail 3 inches long. Anyone
who has ever
tasted blood knows that it has a slightly metallic taste. This is due to
the high levels of
iron in the blood. If you were to take all of this iron out of the body,
you’d have enough
to make a small nail and very severe anemia.
88. The most common blood type in the world is Type O. Blood banks find
it valuable as
it can be given to those with both type A and B blood. The rarest blood
type, AH
or Bombay blood due to the location of its discovery, has been found in
less than hundred
people since it was discovered.
89. Human lips have a reddish color because of the great concentration of
tiny
capillaries just below the skin. The blood in these capillaries is normally
highly
oxygenated and therefore quite red. This explains why the lips appear pale
when a person
is anemic or has lost a great deal of blood. It also explains why the lips
turn blue in very
cold weather. Cold causes the capillaries to constrict, and the blood loses
oxygen and
changes to a darker color.

Miscellaneous

Here are a few things you might not have known about all different parts
of your anatomy.
90. The colder the room you sleep in, the better the chances are that you’ll
have a bad
dream. It isn’t entirely clear to scientists why this is the case,
but if you are opposed to
having nightmares you might want to keep yourself a little toastier at night.
91. Tears and mucus contain an enzyme (lysozyme) that breaks down the cell
wall of
many bacteria. This is to your advantage, as the mucus that lines your nose
and throat,
as well as the tears that wet your eyes are helping to prevent bacteria
from infecting those
areas and making you sick.
92. Your body gives off enough heat in 30 minutes to bring half a gallon
of water to a
boil. If you’ve seen the Matrix you are aware of the energy potentially
generated by the
human body. Our bodies expend a large amount of calories keeping us at a
steady 98.6
degrees, enough to boil water or even cook pasta.
93. Your ears secrete more earwax when you are afraid than when you aren’t.
The
chemicals and hormones released when you are afraid could be having unseen
effects on
your body in the form of earwax. Studies have suggested that fear causes
the ears to
produce more of the sticky substance, though the reasons are not yet clear.
94. It is not possible to tickle yourself. Even the most ticklish among
us do not have the
ability to tickle ourselves. The reason behind this is that your brain predicts
the tickle
from information it already has, like how your fingers are moving. Because
it knows and
can feel where the tickle is coming from, your brain doesn’t respond
in the same way as it
would if someone else was doing the tickling.
95. The width of your armspan stretched out is the length of your whole
body. While not
exact down to the last millimeter, your armspan is a pretty good estimator
of your height.
96. Humans are the only animals to produce emotional tears. In the animal
world,
humans are the biggest crybabies, being the only animals who cry because
they’ve had a
bad day, lost a loved one, or just don’t feel good.
97. Right-handed people live, on average, nine years longer than lefthanded
people do. This doesn’t have a genetic basis, but is largely due to
the fact that a majority of the
machines and tools we use on a daily basis are designed for those who are
right handed,
making them somewhat dangerous for lefties to use and resulting in thousands
of
accidents and deaths each year.
98. Women burn fat more slowly than men, by a rate of about 50 calories
a day. Most
men have a much easier time burning fat than women. Women, because of their
reproductive role, generally require a higher basic body fat proportion
than men, and as a
result their bodies don’t get rid of excess fat at the same rate as
men.
99. Koalas and primates are the only animals with unique fingerprints. Humans,
apes
and koalas are unique in the animal kingdom due to the tiny prints on the
fingers of their
hands. Studies on primates have suggested that even cloned individuals have
unique
fingerprints.
100. The indentation in the middle of the area between the nose and the
upper lip
has a name. It is called the philtrum. Scientists have yet to figure out
what purpose this
indentation serves, though the ancient Greeks thought it to be one of the
most erogenous
places on the body.